Multiple temperature refrigerator



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MULTIPLE TEMPERATURE"REFRIGERATOR Filed March 19, 1945 March 4, 1947.-

Patented Mar. 4, 194'."

v 2,416,777 i. MULTIPLE TEMPERATURE REFRIGERATOR Edmund F. Schweller, Daytom-Ohio, assignor to General Motors Corporation, Dayton, 0h10, a

corporation of Delaware Application March 19, 1945, Serial No. 5843,620

(Cl. GIZ-116) 4 Claims. 1

This invention relates to refrigeration and particularly to a refrigerator cabinet having compartments maintained at different temperatures relative to one another.

It is an increasing problem in household refrigerator cabinet construction to' provide for the freezing of certain substances While at the same time providing separate and different temperatured compartments for the storage of various food products. Present day refrigeration demands in the ordinary household, include along with a compartment for freezing water or desserts, etc., for table use and a compartment Where cooked food products and raw vegetables and the like may be stored without undue drying, ample space or a fairly large compartment for the storage of pre-frozen meats, berries, vegetables, etc.

It is a refrigerator manufacturers problem to meet these demands 'without materially increasing the size of a refrigerator cabinet and to economically refrigerate such compartmentsto difyferent temperatures relative to4 one another.

An object of my invention is to provide an improved refrigerating apparatus of the household refrigerator type wherein the evaporator of a primary refrigerating system cools. one compart- .ment to a predetermined low temperature andv is utilized for rendering a plurality of other closed refrigerant circuits effective to cool other compartments of the refrigerator to diierent ternperatures relative to one another.

Another object of my invention' is to provide an' improved household refrigerator having superimposed food storage compartments the intermediate compartment of which is cooled by an evaporator of a primary refrigerating system and the compartments above and below the intermediate compartment cooled by closed secondary refrigerant circuits rendered eiective by the primary evaporator and one of which circuits has capillary means therein for lifting liquid refrigerant upwardly.

,A further and more specic object of my invention is to provide a household refrigerator with a plurality of separate compartments all insulated from one another and to arrange a refrigerating system and closed refrigerating ,circuits within the refrigerator in such a manner as to refrigerate the compartments to different temperatures relative to one another whereby freezing of substances may take place in one compartment, a temperature maintained within another compartment for holding pre-frozen foods and a higher temperatured compartment of higher relative humidity for the storage of certain other food products.

Further objects and advantagesof the present invention will be apparent from the following description, reference being had to the 4accom- Danying drawings, wherein one form of the present invention is clearly shown.

In the drawings: Fig. 1 is a front view of a refrigerator cabinet having my invention embodied therein; and

Fig. 2 is an enlarged side vier.1 partly in elevation and partly in lvertical section of the refrigerator cabinet disclosed in Fig. 1.

Referring to the drawings, for illustrating my invention, I have shown in Fig. Il thereof a. refrigerating apparatus .of the household type. This apparatus comprisesa cabinet i!) enclosed in metal Walls i i and provided with three superimposed or vertically aligned food storage compartments i2, it and id, formed by metal liners i5, it and il (see Fig. 2), and being normally closed by doors it, it and 2@ respectively and a lower machine compartment il closed by a door 22. Any suitable insulated material 24 may surround the metal liners beneath. the metal walls i i for insulating the compartments from one another. It is to be understood that a single door may be provided for simultaneously closing all three of the food storage compartments ifdesired instead of employing the separate doors. In

' the present structure it is intended that the com- Sii partment i2 be utilized for the storage of prefrozen food products such as meats, berries, vegetables, etc., compartment l@ for freezing desserts for table use or water into ice blocks or cubes, Within suitable trays indicated at 25, and compartment iii for raw vegetables, milk, etc., and for food products left over from one meal to another. However, it is to be understood that any desired arrangement and use of the compartments might be made.

A closed primary reirigerating system associated with cabinet it includes an evaporator comprisinga conduit it, coiled back and forth horizontally across and in intimate thermal conof the motor-compressor unit 34. Operationof the unit 34 causes evaporated refrigerant in the 1 conduits 28, 21 and 28 of the evaporator to be' A4withdrawn therefrom and circulated into the ;casing of unit 34. The compressor of unit 34 compresses the refrigerant and forwards same l under pressure. through conduit 33, into the con- 1 denser 32.- The` compressed refrigerant may be cooled in any suitable or desirable manner in condenser 32 to liquefy the same therein. Liquidl refrigerant is conveyed, byvv pipe or conduit 3|, l from condenser 32 in series through conduits 26, 21 and 28 of the evaporator. under the control 1 of any well known or conventional restrictor or 1 expansion valve indicated at` 35, for re-evaporation therein to remove heat from the intermediate compartment lI3 and for a purpose to be presently described. The motor-compressor unit 34 may be started and stopped in any one of a 1 plurality of well known or conventional manners 1 (not shown). control the operation of unit 34 in response to l the temperature of compartment I3' so that the freezing of desserts or water will be given prefer- 1 ence in an apparatus of the type disclosed.

However, it may be desirable to Lower food storage compartment I4 is cooled to of the primary refrigerating system. This closed circuit includes a at tank-like refrigerant condensing portion 4I having a, plurality of pipes or refrigerant evaporating portions 42 communicat- `ing therewith and extending downwardly therefrom over and in intimate thermal contact with .'walls of metal liner I1 of compartment I4. The top wall of tank 4I is secured in intimate thermal Icontact with the conduit coil portion 28 of the primary evaporator. 1 tirely around the side walls and bottom of liner I1 or they may terminate adjacent a central point Pipes 42 may extend enalong the liner bottom wall. Refrigerant in this 1 circuit vaporizes within the pipes 42, upon absorb- 1 ing heat from compartment I4, through the walls thereof, and the evaporatedrefrigerant rises to tank 4I wherein it is cooled by the refrigerating eiect produced by coil 28, and liquefied. 'I'he :liquefied refrigerant then flows downwardly in 1 pipes 42 for re-evaporation therein. In order to cool the upper cold storage compartl ment I2 by another closed secondary refrigerat- 1 ing circuit rendered effective by a primary evappipe or conduit as, to the 'suction side or inietof this secondary circuit the volatile liquid refrigerant therein will climb, due to'capillary action, up through the porous capillary structures or rods 48 in the tubes 41 where it will evaporate upon absorbing heat from compartment I2 through walls thereof. 'I'his evaporated refrigerant will collect in the upper portion of tubes 41 and by progressive accumulation there, together with its tendency to ow to the coldest portion of the circuit, will be forced down through the passage at the side of the rods 48 andwil escape through the liquid refrigerant to the space above the level thereof within tank 46 Where it will condense. In

`this manner, heat is transmitted downwardly yfor controlling `entrance of refrigerant into the primary` evaporator. It is well known that this ,a temperatureconsiderable abovethat of comt partment I3 by a closed secondary circuitcontaining a volatile refrigerant and rendered effective by lrefrigeration produced by the evaporator By the arrangement disclosed freezing within compartment I3 may occur at very low temperatures while at the same time permitting functioning of the secondary circuit, associated with the portion or coil 26 of the primary evaporator, to produce a holding temperature of approximately 24 to 28 F. within the pre-frozen food storage compartment I2. The condensing portion -of the secondary circuit, employed to cool the lower compartment, being in contact with the coilV portion 28 of the evaporator of the primary refrigerating system will permit this circuit to function to produce a somewhat higher temperature within compartment I4 for the preservation of food products required to be stored in temperatures of say for'example from 40 to 50 F.

From the foregoing it will be seen thatI have provided an improved household refrigerating ap.. paratus wherein compartments thereof are insulated one from another and maintained at different temperatures relative to one another by rendering two secondary refrigerant circuits operative by a novel arrangement or association thereof with an evaporator of a primary refrigerating system. The construction and arrangement of a refrigerating apparatus as herein disclosed meets substantially 'al1 o1' the refrigeration requirements encountered in the ordinary household.

`the side walls and partially across the top wall of metal liner I5 of compartment I2. These tubes 41 are constructed in accordance with the disclosure of the Gaugler patent referred to and each' z includes'a sintered or porous metal rod 48 forming i a capillary means positioned therein and extendl ing below 4the end of the tubes into liquid refrig- I erant within the tank 48. A passage is provided The construction is compact and does not materially increase the over-al1 size of a household refrigerator.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, as may come within the scope'of the claims which follow.

What is claimed is as follows: l

l. A refrigerating apparatusl comprising in. combination, a-cabinet having therein an upper food storage compartment, a lower food storage compartment and an intermediate compartment.

cooling said lower compartment including a refrigerant condensing portion in heat 'exchange relationship with the evaporator of said primary refrigerating system and refrigerant evaporating portions extending into heat exchange relationship with said' lower compartment, another closed secondary circuit containing a volatile liquid refrigerant for cooling said upper compartment, and said-another closed secondary circuit includ'- ing a refrigerant condensing portion in heat exchange relationship with the evaporator of said primary refrigeratingsystem and refrigerant evaporating portions extending upwardly into heat exchange relationship with said upper compartment.

2. A refrigerating apparatus comprising in combination, a cabinet having therein an upper food storage compartment, a lower food storage compartment and an intermediate compartment all insulated from one another, a closed primary refrigerating system associated with said cabinet and including an evaporator for cooling said. in#- termediate compartment, a closed secondary circuit containing a volatile liquid refrigerant for cooling said lower compartment including a refrigerant condensing portion in heat exchange relationship with the evaporatorof said primary refrigerating system and refrigerant evaporating portions extending into heat exchange relationship with said lower compartment, another closed `secondary circuit containing a volatile liquid refrigerant for cooling said upper compartment, said another closed secondary circuit incl ng a refrigerant condensing portion in heat exchange relationship with the evaporator of said primary' refrigerating system and refrigerant evaporating portions extending upwardly 'into heat exchange relationship with said upper compartment, said another closed circuit containing capillary means extending from said condensing portion to said evaporating portion thereof and also having connecting passages extending between said portions, and said capillary means being in contact with liquid refrigerant in the condensing portion of said another crcuit.

` cluding a refrigerant condensing portion in heat exchange relatonship with the evaporator of said primary refrigerating system and refrigerant evaporating portions extending in heat exchange relationship over a plurality of walls of said lower compartment for cooling the interior thereof through said walls, another closed secondary circuit containing a volatile liquid refrigerant for cooling said upper compartment, said another closed secondary circuit including a refrigerant condensing portion in heat exchange relationship with the evaporator of said primary refrigerating system and refrigerant evaporating portions extending upwardly into heat exchange relationship with said upper compartment, said another closed circuit containing capillary means extending from said condensing portion to said evaporating portions thereof and also having connecting passages extending between said portions, and said capillary means being in contact with liquid refrigerant in the condensing portion of said another circuit.

4. A refrigerating apparatus comprising in combination, a cabinet having therein an upper food storage compartment, a lower food storage compartment and. an intermediate compartment all insulated from one another, a closed primary refrigerating system associated with said cabinet and including an evaporator for cooling said intermediate compartment, said evaporator. comprising a. first cooling portion in contact with the upper wall of said intermediate compartment and a second cooling portion in contact with the lower wall of said intermediate compartment, a closed secondary circuit containing a volatile liquid refrigerant for cooling said lower com-` partment including a refrigerant condensing portion in heat exchange. relationship with said second cooling portion of said primary evaporator and refrigerant evaporating portions extending over walls of said lower compartment in contact therewith, another closed secondary circuit containing a volatile liquid refrigerant for cooling said upper compartment, and said another closed secondary circuit including a refrigerant condensing portion in heat exchange relationship with said first cooling portion of said primary evaporator and refrigerant evaporating portions extending over walls of said upper compartment in contact therewith.

` EDMUND F. SCHWELLER.

REFERENCES CITED UNITED STATES PATENTS 2,154,299 Bixler Apr. 11, 1939 

